Endocrine System: The Hypothalamic–Pituitary Axis
1. The anterior pituitary is composed of ______tissue. Name the six classic hormones whose functions are well known.
a.
b.
c.
d.
e.
f.
2. TRH, GNRH, CRH etc. are known as ______hypothalamic hormones which regulate the function of the ______pituitary. These hormones are released into capillary beds and carried directly to the pituitary by the ______located in the ______.
3. ______and ______, the posterior pituitary hormones are synthesized in the ______and ______nuclei of the hypothalamus. They are stored in the axon terminals located in the ______pituitary. Similar to neurotransmitters, an ______in the neuron causes their release.
4. In negative feedback, the target hormone feeds back to alter the release of the anterior or hypothalamic hormones thus (increasing or decreasing) its own release.
5. Give an example of a hormone that has negative feedback mainly to the anterior pituitary. ______
Give an example of a hormone that has negative feedback to both the anterior pituitary and the ventral hypothalamus. ______
6. Prolactin is unique in that the main ventral hypothalamic hormone regulating its secretion (______), inhibits its release.
______(hormone) increases prolactin release. Very high levels of this hormone during pregnancy actually block the effect of prolactin on milk production.
7. ______hormones are necessary for the release of ______hormone. This is an example of modulation of a hormone by a target hormone of another series.
8. Suckling of an infant causes milk letdown by stimulating what hormone? ______
Changes in osmolarity detected by chemically sensitive neurons in the hypothalamus will alter what hormone’s level? ______
9. Cortisol release is synchronized by the light/dark cycle and has a 24 hour pattern of secretion known as a ______rhythm. Levels are highest at what part of the day? ______
10. Besides controlling levels of T3 and T4, TSH also promotes ______of the thyroid gland. T3 and T4 are carried in the blood stream bound to ______because they are (hydrophilic or lipophilic).
11. T3 and T4 enter the target cells by ______and bind to receptors located ______. T3 and T4 are synthesized from ______and ______.
12. Which of the following would be symptoms of hypothyroidism also known as ______?
lethargy or hyperexcitability
high BMR or low BMR
high heart rate or low to normal heart rate
feeling cold or sweating
weight loss or weight gain
13. Lack of dietary iodine would cause (primary or secondary) hypothyroidism and the patient would probably get an iodine-deficient ______.
14. Graves’ disease is the most common cause of primary ______. The body secretes ______, which mimics the action of TSH and thus may cause a ______as well as high levels of thyroid hormones.